I've already a subscription to Object Desktops. This subscription is going to end in 21 days.

The ending of the subscription period is the end of access to new/updated software.

Provided you have downloaded and archived any/all the apps you're interested in...within the subscription period...and you record the activation licence, you can continue to use [and reinstall] that software until the end of time. They do not expire.

As with any and all 'subscription' processes - when the period ends so does your access to new editions...